On Mar 13, 2008, at 8:02 AM, Stefano Bortolotti wrote: > I have tried this: >>> t = Time.now > => Thu Mar 13 12:57:47 +0100 2008 >>> t1 = Time.now + 1.hours > => Thu Mar 13 13:58:03 +0100 2008 >>> t2 = t1 - t > => 3615.968256 >>> tot = Time.at(t2) > => Thu Jan 01 02:00:15 +0100 1970 > > but I don't know why the difference between t1 e t is 2 hours and > not 1 > hour? irb> t = Time.now => Thu Mar 13 09:26:37 -0400 2008 irb> t1 = Time.now + 3600 => Thu Mar 13 10:26:56 -0400 2008 irb> t2 = t1 - t => 3618.385132 irb> Time.at(t2) => Wed Dec 31 20:00:18 -0500 1969 Because you're not looking at the time zone (+0100). -Rob Rob Biedenharn http://agileconsultingllc.com Rob / AgileConsultingLLC.com